Heat Illness & Hydration John Neidecker, DO, ATC Sports Medicine Physician Cooper Bone & Joint Institute

Why do we sweat? To cool the body down High body temperatures can lead to organ damage As muscles contract – heat is produced

How do we sweat? Neurological response Skin blood vessels vasodialate – stimulating sweat glands Sweat evaporates and cools the skin

What does sweat contain? Water Urea Electrolytes –Sodium

The composition is highly variable between individuals Person Environment Body weight Acclimated/Fitness level

Performance & Hydration Performance has been shown to decrease secondary to dehydration –Physically –Mentally Decreases start to happen when there is a decrease in total body water of 2%

Performance & Hydration People do not perceive the feeling of being thirsty until there is a decrease in total body water of 3%

When things go wrong… Sweat response becomes dysfunctional resulting in –An increase in body temperature –An electrolyte imbalance

Electrolyte Imbalance Levels too high or too low can cause –Arrhythmias –Seizure –Brain damage

Hyperthermia Increase in body temperature can lead to –Heat Stroke –Heat Exhaustion –Heat Cramps

Heat Stroke Defined by –Body temp > 104 F –CNS Dysfunction –Organ Damage

Heat Exhaustion Inability to continue exercising Brain mediated “safety break” Temperature not as high as HS

Heat Cramps Painful muscle cramps –calves Associated with large amounts of sodium loss

Who’s at risk for heat illness? Those who have had it before Out of shape/Unacclimatized Overweight Age

Warning signs Change in mental status Dizziness Difficulty walking Vomiting Hyperventilation

Confused with Concussion Take a temperature

What to do if suspected Remove athlete from play!!!!! Call EMS Place athlete in a shaded area Ice –Emersion –Bags on head, neck, armpits, groin

Quick Aside Sickle Cell Trait –Not a heat illness –Crisis triggered by Dehydration Hypoxemia –NCAA D1 – Screening –Does not disqualify from participation

Prevention Go into practice fully hydrated Wear light colored, loose fitting clothing Exercise during the cooler parts of the day Acclimate over time –Start days before training camp –Start at 10 minutes –Increase by another 10 minutes every 2 days

Hydration Guidelines Drink 16 oz of water or sports drink one hour before exercise Drink 4-8 oz every minutes of exercise Exercising less than an hour, drink water Exercising more than an hour, drink a sports drink »16 oz is about half a liter

After Exercise Hydration Weigh yourself before and after practice –For every 2 lbs lost drink 48 oz If your urine is dark – you are not drinking enough

History of Gatorade Created by researchers at the University of Florida in 1965 –“Gator”-aid Legend of the 1967 Orange Bowl win over Georgia Tech

Pickle Juice Anecdotally, helps with muscle cramps High in sodium

Chocolate Milk Post-work out drink Increase protein synthesis Increases muscle glycogen 16 oz about 40 min after work out Low-fat

References Armstrong, LE, et. al, American College of Sports Medicine Position Stand: Exertional heat illness during training and competition., Med Sci Sport Exer pgs Sawka, MN, et. al, American College of Sports Medicine Position Stand: Exercise and fluid replacement., Med Sci Sport Exer pgs